Obs. : 2016-04-23 Planet Ly alpha (photons/cm^2/sec) Mercury 4.013e+11 Venus 4.065e+11 Earth 3.897e+11 Mars 3.935e+11 Jupiter 3.741e+11 Saturn 3.935e+11 Uranus 4.065e+11 Neptune 3.990e+11 Pluto 3.989e+11